No speed difference with 2 or 3 raptors

[DarphB]

Well, I just got my 3rd 74gb raptor.
Tried to install it, with my other 2 raptors on my p5ad2-e mainboard. Plenty of connections (8 SATA connectors).

Went into the Intel controller config, deleted the current array.
Tried to create a new stripe with 3 drives and it wouldnt let me.
Found out, that the Intel ICH6 controller will not do 3 drive stripe.

SO, I connected the drives to the Silicon Image controller.
Created the array with no problem.

Installed Winxp and patched it up.
1st thing I installed was HD Tach.
Did some benching.
91MB/s which is about the same as when I had 2 Raptors connected in a stripe....

Shouldnt I be seeing alot better performance than this with the extra drive???
Or is the Silicon Image controller a piece of junk?

Ideas?

 

[Gamingphreek]

You are still running a RAID-0 Array. Shouldn't notice much of a difference.

If you want a difference, you now have 3 drives and are able to use RAID-5. If you use that you SHOULD see a small increase in Synthetic Benches, and HDTach. None of these are really going to affect gaming, and whatnot though.

-Kevin

 

[YOyoYOhowsDAjello]

article

 

[Vegito]

Originally posted by: Gamingphreek
You are still running a RAID-0 Array. Shouldn't notice much of a difference.

If you want a difference, you now have 3 drives and are able to use RAID-5. If you use that you SHOULD see a small increase in Synthetic Benches, and HDTach. None of these are really going to affect gaming, and whatnot though.

-Kevin

3 drive RAID 0 will notice a difference.

RAID 5 is slower than raid 0 because you need to calcaulate parity bit, not faster. In fact, its known, RAID 5 is slower in write. Especially in IDE RAID 5 w/o cache.. cache is the only thing thats making raid 5 keep up to raid 0 in write speed.

Raid 0 has no over head and no protection at all

http://www.amsstorage.com/html/raid_overview.html

 

[Gamingphreek]

Yes however correct me if i am wrong...

RAID 1 has very fast read times, and much more stable (As it is mirroring and all)

RAID 0 has very fast write times, and no protection

RAID 5 combines the best of both worlds

Of course this is the "In a nutshell version" because im really lazy but, isn't that the general idea.

-Kevin

 

[Pariah]

HDTach has issues with RAID arrays. If that is average STR, it's right about where it should be. If it is peak STR, than you're about 20-30MB/s slower than where you should be.

Switching ATA RAID controllers with a 2 drive RAID 0 should result in about 0% performance difference no matter from how bad to how good you are going.

Under ideal conditions, you are right Gamingphreek, except that ideal conditions don't happen with ATA.

RAID 1 - possibly faster reads, vast majority of ATA controllers don't load balance reads, so no help

RAID 0 - fastest reads and writes

RAID 5 - flat out awful write performance with majority of controllers, pretty good read performance, though still slower than RAID 0 with the same number of drives

Dedicated CPU and highly optimized drivers are more vital for RAID 5 performance than cache. Though cache certainly does help.

 

[imported_Phil]

Originally posted by: Gamingphreek
Yes however correct me if i am wrong...

RAID 1 has very fast read times, and much more stable (As it is mirroring and all)

Nope. RAID-1, with the appropriate, decent controller, will perform read striping. The vast majority of controllers will not accelerate the reads.

Also, mirroring != stability.

RAID 0 has very fast write times, and no protection

It also has the fastest read times.

RAID 5 combines the best of both worlds

Nope. God-awful write times unless you have a rather expensive RAID card with a decent amount of hardware cache.

 

[MDE]

The Silcon Image controller is choked by the PCI bus (at least on burst speeds). My dual Raptors hit maybe 95 MBps burst on HD Tach on a SiL controller, but hit 195+ MBps on my nForce3 Ultra board.

 

[DarphB]

Ok, great input...
So, would I be better off, going back to the Intel ICH6 controller and 2 74's striped? Or leave it as it is?

Or?????